class Person {
    public Person() {
        System.out.println("无参的构造方法被调用了...");
    }

    public Person(int age) {
        this();
        System.out.println("参的构造方法被调用了...");
    }
}

public class Ex11 {
    public static void main(String[] args) {
        Person p = new Person(18);
    }

}